Lowdown: VSS/"speed sense", Kenwood, Wireless CarPlay

[evofxdwg]

I asked Kenwood (email support) the following and am waiting on an answer. Maybe someone here knows the answer.

Ive been researching Kenwood high end receivers (DMX1037S, DMX1057XR, DNR1007XR) with 10.1 inch screens to go in my 2021 Newmar motorhome (replacing the junky Xcite system). The question refers to having to connect the VSS (vehicle speed signal: "speed sense") in order to use Apple wireless CarPlay. The Kenwood manuals mention both the "speed sense" wire and a GPS ANTENNA (included). Do I need both? What do I lose if VSS not connected? There are internet videos and forum posts from 2019 that say Kenwood did a firmware update to do away with the VSS hookup requirement. What is required in 2022 on the Kenwood units mentioned?

Part 2 (asked here only): From a Freightliner wiring drawing (from dtnaconnect) , there is a VSS signal avialable on one of the bodybuilder connectors (see pix). But, by signal name only ("PWM signal), this might be a pulse width modulation signal. Is it even compatible with the VSS needed by the modern receivers?

[dizcom]

No idea, but I just replaced the stereo in our rig with a modern one and it uses it's internal GPS to determine speed. It doesn't need the vehicle to tell it how fast it's going to use CarPlay. Got a harness from Amazon that plugged directly into the Freightliner harness and didn't have to wire anything special, just the two harnesses together. There was no VSS wire in either harness.

[evofxdwg]

Originally Posted by dizcom

No idea, but I just replaced the stereo in our rig with a modern one and it uses it's internal GPS to determine speed. It doesn't need the vehicle to tell it how fast it's going to use CarPlay. Got a harness from Amazon that plugged directly into the Freightliner harness and didn't have to wire anything special, just the two harnesses together. There was no VSS wire in either harness.

1. Are you using WIRELESS CarPlay?
2. Can you ID the company making or website selling the Freightliner harness?

Thanks

[dizcom]

Yup, wireless. It's awesome.


Here's a link to the harness: https://www.amazon.com/dp/B09CTLCRK6...ing=UTF8&psc=1

[Chief6722]

Evofxdwg… have you verified or asked if the DMX1037S, 1057XR or DNR1007 have the RV or Truck profile capabilities?

I had an Alpine Navigation system in one of my RV’s but it didn’t have the RV/Truck profile and it pretty much sucked because it got me into a bind several times from trying to send me down a route that only a car or small truck could make and I had to buy a more specific Garmin unit.

I’m definitely interested in the DNR1007 but can’t find anywhere that it says anything about the RV/Truck option.

[Suburbazine]

Originally Posted by Chief6722

Evofxdwg… have you verified or asked if the DMX1037S, 1057XR or DNR1007 have the RV or Truck profile capabilities?

I had an Alpine Navigation system in one of my RV’s but it didn’t have the RV/Truck profile and it pretty much sucked because it got me into a bind several times from trying to send me down a route that only a car or small truck could make and I had to buy a more specific Garmin unit.

I’m definitely interested in the DNR1007 but can’t find anywhere that it says anything about the RV/Truck option.

Don't use Carplay/AA in this case. Just use the wireless screen mirroring feature to display your choice of RV navigation from the mobile device. I use Copilot GPS mirrored to my Xite system, until I can afford to put in a DMX1037 at least.

[evofxdwg]

Originally Posted by Chief6722

Evofxdwg… have you verified or asked if the DMX1037S, 1057XR or DNR1007 have the RV or Truck profile capabilities?

I had an Alpine Navigation system in one of my RV’s but it didn’t have the RV/Truck profile and it pretty much sucked because it got me into a bind several times from trying to send me down a route that only a car or small truck could make and I had to buy a more specific Garmin unit.

I’m definitely interested in the DNR1007 but can’t find anywhere that it says anything about the RV/Truck option.

Kenwood answered an email and stated the DNR1007XR is not available with RV-specific Garmin navigation software. It is only available with car-type navigation. The DMX1057XR and DMX1037S do not run navigation at all. So there is not currently a solution for embedded RV specific navigation on any of the Kenwood, Pioneer, or Alpine high end/big display receivers.

It would be nice to have RV-specific nav on the infotainment system but there are iPhone apps available, such as CoPilot, RVLife, etc., that do. I haven't looked thoroughly at any of those yet. We don't really have much of a problem using Apple Maps or Google maps, and sometimes Waze. But I want a decent map display to replace the Xcite/Rand McNally nav on a 10 inch or so display so just looking at systems with CarPlay, and WIRELESS CarPlay.

Im just reverse engineering my coach Xcite/amp/camera/display wiring now. I also took a casual look at some Kenwood and Pioneer unit wiring signals. You might be surprised to find out, the original Kenwood (and other vendors) units that supported WIRELESS CarPlay required the VSS signal for WIRELESS CarPlay to operate. Use of the signal has nothing to do with navigation.

Later units, and the Kenwood 1007 (with a firmware update as confirmed by another Kenwood email), now use a GPS antenna to synthesize the vehicle speed information for WIRELESS CarPlay to operate. It looks like they had to do this because the transportation industry has not standardized the electrical format of typical VSS signals, or some vehicles did not provide convenient access, or none at all.

I never found out WHY WIRELESS CarPlay requires vehicle speed information. But I speculate it's something the lawyers required to prevent certain apps (like movie player) from running if the vehicle is moving.

Oh and while reverse engineering the wiring, I found I can, with a lightning-to-HDMI adapter cable (from Amazon), repeat an iPhone screen and audio on the main 10" Xcite display. I just plugged into the HDMI port on the front of the Xcite unit (under the dash cover on a 2021 Canyon star) and selected "HDMI" on the menu screen. (It may not work if the parking brake is off but I have a fix for that if needed). It is not CarPlay and the touchscreen function does not work. But it will display the iPhone navigation screen my wife is operating.

[evofxdwg]

Originally Posted by Suburbazine

Don't use Carplay/AA in this case. Just use the wireless screen mirroring feature to display your choice of RV navigation from the mobile device. I use Copilot GPS mirrored to my Xite system, until I can afford to put in a DMX1037 at least.

Wireless screen mirroring? Im interested in that. I haven't found any such capability in my Xcite system or mentioned in the manual (XSG3NA - see label pix below). Which one do you have, and what do you select on the Xcite MENU screen to wirelessly mirror? What settings on your phone when you do it?

[Sandood]

Originally Posted by evofxdwg

The DMX1057XR and DMX1037S do not run navigation at all.

So, I'm just finishing up installing the Kenwood DMX1057XR in my 2022 Thor Chateau, replacing the POS Axxera (no Carplay) that came installed in it.

Fired it up today, and the RV Life GPS app is one of the apps supported by (Wireless) Apple Carplay!! Fired it up, selected a destination, and after it verified my subscription it started giving me directions.

There is an add-on device that will get the VSS speed sensor from the OBD2 port (search for Kenwood KNA-SPM100 Speed Pulse Adapter for Models with Wireless Carplay). I haven't installed mine yet, because I need ACC power, not full-time power (like the radio and camera switcher that Thor wired in) - otherwise the SPM100 always reports an error (it apparently expects the ODB2 port to be live whenever the SPM100 has power). Thor apparently hid/removed/didn't run ACC beck to the back of the radio, just always-on 12vDC.

Kenwood also provides a firmware update for the 1057XR that supposedly removes the requirement for the speed sense wire altogether.

I learned a LOT of the above from the Crutchfield site, under the description, reviews, and details tabs for the 1057XR (esp the info about the SPM100 and the firmware update). I always suggest people use Crutchfield for aftermarket radios - they are really the best source for information, and if you buy from them, you get primo support and warranty assistance.

[Sandood]

Originally Posted by evofxdwg

Use of the signal has nothing to do with navigation.

Not true. VSS is used to track your location when the GPS signal is unavailable, e.g., when you are in a tunnel or on the lower deck of a bridge like the GW bridge in NYC.

I do think that only wireless Carplay wants the VSS data; if you use wired, I think the phone itself just guesstimates your distance travelled by your speed before GPS was lost.

[GoingRD]

Originally Posted by dizcom

No idea, but I just replaced the stereo in our rig with a modern one. Got a harness from Amazon that plugged directly into the Freightliner harness and didn't have to wire anything special, just the two harnesses together.

Thanks, dizcom, for the posts. I've ordered the Kenwood DMX1037S and I have a question about the harness you purchased from Amazon and used in your installation.
Is this the procedure?
1. Unplug the coach's DIN connector from the back of the old radio.
2. Use the harness to go between the coach's DIN connector and the DIN connector that comes with the Kenwood, matching the colors of the harness to the Kenwood DIN.
And that's it?

Was a special tool needed to remove the old radio?

[Suburbazine]

Originally Posted by evofxdwg

Wireless screen mirroring? Im interested in that. I haven't found any such capability in my Xcite system or mentioned in the manual (XSG3NA - see label pix below). Which one do you have, and what do you select on the Xcite MENU screen to wirelessly mirror? What settings on your phone when you do it?

For some reason I never saw this- I use a Miracast wireless HDMI system to mirror my phone to my Xite.

[evofxdwg]

Update from OP here:

Original post answer: The need for connection to the VSS signal is replaced in Kenwood and other brand later units by having a GPS antenna included. Presumably because some vehicles didn't have a VSS signal and/or there appears to be no common signal standard. So that problem goes away.

That being said, in my motorhome, I found the Xcite rear view camera in my rig has a proprietary and uncommon interface, with video down, control commands and power up a single coaxial cable. The camera has 3 angle/magnification views and guidelines when in reverse, all implemented in the camera itself. Thus digital commands are sent from the Xcite receiver head so I cant easily replace it without changing the rear camera and incurring all the possible added wiring issues and extra expense. One solution would be leaving the Xcite receiver head in place and powered just for rear/side camera function, and move all audio function to a new Kenwood, since we solved the Nav problem already (Got a Garmin 1090). Seems Rube Goldberg to me though. (The side cameras seem to be conventional 2-wire video with separate power and are switched thru a River Park CVS-300 switcher, which is already Rube Goldberg if you ask me!)

We solved the Nav problem by adding a Garmin 1090 with dash mount that worked out quite well on our 3.5 month western US trip this past summer. I cant really justify the expense of just improving sound quality due to cabin noise while driving, and can just switch over to the Bose sound bar when parked.

So I will not be changing the receiver system anytime soon, despite the awful Rand McNally navigation (now not used due to having the Garmin) and somewhat crappy sound quality of the Xcite and its amp/speaker system. I was also lusting after a nice replacement set of component speakers including separate tweeters mounted on the A pillars.....sigh.